7 Tips For Restarting a Hydraulic Pump After an Extended Shutoff Period

We are all aware of the importance of regular use in the maintenance of mechanical parts. It’s the reason we run the engine and air conditioning in a car every 2-3 weeks when a vehicle is going to be out of service for a short period. In terms of hydraulics, it is advised to perform basic maintenance on hydraulic systems in regular intervals to ensure long service life and smooth working. But what if despite the best intentions your hydraulic pump has been shutoff for a long period?

Long term shutoff of hydraulic machinery may result in damage to the system components due to corrosion, lack of lubrication, contamination and more. Hydraulic pumps are an extremely important component of every hydraulic machine, with the role of pressurising hydraulic oil. If a system has not been maintained properly during the shutoff period, the damage may be severe and potentially the entire system could fail.

When restarting the system, it is strongly suggested that the service technician complete the following checks:

1. Confirm that the pump is spinning freely. There’s a chance that the pump could contain solidified product or have mechanical issues from sitting idle. In order to spin the pump the technician should lockout of the prime mover, remove the coupling guard and then turn the shaft. Any rust, contamination, or other mechanical issue will prevent the pump from spinning freely and/or cause noises while turning. In such conditions it is important not to force the pump to move, and instead inspecting it by removing from the machinery. 

2. Inspect the condition of the coupling and mechanical seals. This includes looking for any evidence of wear, such as rubber dust or plastic chunks under the coupling (this may be evidence of misalignment). Checking the mechanical seal before restarting will also help to detect system leakage and related injuries.

3. Complete an oil sample and check lubrication levels. A sample of oil should be taken to test for containments and oil properties monitored. It is also important to ensure all moving components in the system are lubricated properly for safe and efficient working.

4. Check clamps, connections and hoses. Properly inspect hoses, clamps and connections to prevent leakages and related issues. If a loose connection is found, tighten it properly.

5. Double-check filters and valves. Before restarting, check important filters like suction, pressure, and return filter, and replace the dirty/damaged filters. Also ensure all hand valves that need to be open are open, including all pressure and return line hand valves.

6. Prime and vent the pump. Ensure that the pump is primed and vented, and valves are in the correct position. Also, check the mounting bolt to ensure that the pump is secured safely.

7. Switch on and complete a final check. If all the above-mentioned checks are done properly, then it may be time to safely turn on the system. First, check the compensator settings, and then the relief valve for bypassing and that it is set to the correct pressure. If the relief valve is bypassing, reset the pressures in the system to correct the issue. If is it sill bypassing, the valve may need to be replaced. Inspect all lines and components for leaks. To prevent overheating, take care to clean the tank and valves of dirt and dust. Finally, make sure that all cylinder and motor mechanical linkages are in proper working order.

As always, if a failure were to occur, having spares on hand will reduce the downtime and ensure you’re back up and running quicker. Preventative maintenance to keep your spare pumps in good health while on the shelf. This process may involve:

• Simply turning the input shaft by hand once per month to increase the life of any pump sitting in storage.
• Spraying a light coat of a rust inhibitor on the shaft and coupling to assist with preventing the pump from rusting and corroding.
• Storing the pump in a dry environment at room temperature.
• Storing the pump without oil (just don’t forget to add some before installation).

If you require assistance with a hydraulic pump that has been shutoff for a period, or are looking to purchase a spare pump, please get in touch with our knowledgeable and experienced technicians: http://www.hydraulicdistributors.com.au/files/contact-hydraulic-services-products.php